1. Field of the Invention
The present invention relates generally to agricultural harvesters, more specifically to apparatus for attaching a header assembly to such harvesters, and still more specifically to guides for directing lift arms of the harvester to lift pins on the header assemblies.
2. Description of the Related Art
Agricultural harvesters of many different types commonly incorporate easily attachable and detachable headers to provide flexibility in the type of crop to be harvested, thereby enabling a primary implement unit to be used with a variety of attachments for different types of crops at different times. Along with the flexibility of changing out the header, it has been a goal to make the installation and removal as quick as possible, but at the same time simple and direct so that a single operator can complete the task alone.
Existing header assemblies are usually supported by a pair of lower lift arms pivotally secured to the main body of the agricultural harvester and a third arm between and above the lower lift arm. All three arms are pivotal through appropriate actuators to change the level of the header relative to the ground (and its attitude) to facilitate harvesting of varied crops under different conditions. The connection between the lift arm and the header is accomplished by upwardly facing, U-shaped recesses or cups on the ends of the lift arms, which mate with corresponding horizontal lift pins on the header. Various types of locking mechanisms can be used to ensure that the lift pins, and thus the header, are secured safely to the agricultural harvester.
The upwardly facing U-shaped recesses or cups on the lift arms mating with simple horizontal lift pins on the header enable simple and quick connection of the header to the harvester, so long as the lift arms and lift pins are aligned properly. However, in some harvester arrangements, it is difficult for an operator of the harvester to see the lift pins while advancing the harvester toward the header for connection. For example, on a draper header for a self-propelled windrower, the lift pins are located generally beneath the header, on horizontal elements of inboard struts tucked up under the header where the operator cannot see the pins from the operator's seat on the harvester. Accordingly, the operator cannot see the pins while driving the harvester toward the header to attach the header to the harvester. As a result, it is often necessary for another worker to function as a spotter, directing the harvester operator to the proper position left and right, forward and aft so that the cups on the lift arms engage the lift pins on the header. While a skilled operator familiar with both the harvester and header can develop sufficient familiarity with the proper alignment of the harvester with the header so as to successfully exercise best judgment with the proper positioning of the lift cups with respect to the lift pins, it also can be a source of frustration, and can result in damage to the header, harvester or both when misalignment occurs. The use of a spotter increases the labor required for the simple task of attaching a header to a harvester at a time when the industry is moving toward reduced labor requirements for equipment operation. It can be both costly and inconvenient for a spotter to be available at the time and location required when a header is to be attached to a harvester.
For harvesting some crops, headers are operated very close to the ground, or even riding on the ground. Accordingly, any additional structure projecting lower than the existing header frame and necessary header structure can interfere with the desired header performance.
Since many headers and harvesters have long expected useful operating lives, modifications to either must be backward compatible and/or as simple retrofits so as not to render existing equipment unusable.
Headers may be positioned on the ground, at some elevation on stands or supporting structures, or even on truck beds when the harvester is to be connected thereto. Any modifications to the structures or procedures for completing the attachment must be compatible with all such situations.
Accordingly, what is needed in the art is structure that guides and directs lift arm cups toward lift pins for the attachment of a header to a harvester which can be added as simple retrofits to function with existing header and harvester structures in various applications and uses to facilitate connection by a single worker operating the harvester.